The latest diet furor: a no brainer?

The New England Journal of Medicine has just published a new diet study that is already causing plenty of debate (see the Wall Street Journal’s take on it, for example). The investigators put about 100 people each on one of three diets: low-fat, low-carbohydrate, and Mediterranean. After two years, everybody lost about 6-10 pounds. The low-carb people did best, the Mediterraneans came next, and the low-fat people lost the least – but the differences were not great. The low-fat diet was not really low in fat (30% of calories) but it doesn’t matter. Everybody reduced caloric intake, increased physical activity, lost some weight, and made some metabolic improvements. One funny thing: the study was funded by the Atkins Foundation but the low-carb people were counseled to choose vegetarian sources of fat and protein, not meat. So this was not a test of the Atkins diet. My interpretation: eat less, move more works, and you have choices about how to do the “eat less” part.

Actually, there are vegetarian options on the Atkins diet. The current Atkins format emphasizes avoiding sugars, juices, refined grains, and especially trans fat.

What does seem to happen is that low-carb diets tend to do better because junk food often has a lot of sugar in it, and soft drinks are forbidden on all low-carb regimens. (Low-fat regimens often assumed carbs were in and of themselves slimming, which would mean drinking more soft drinks and pigging out on rice and pasta and especially cereal.)

30% is low; studies have shown that in most people, HDL starts dropping at more than 60% carbohydrate or less than 25% fat. And HDL is a better predictor of a heart attack than LDL.

My own dietary recommendations? Limit total calories, and I find this is easiest for myself with 40-40-20.

Follow Marion

Next public appearance

Grand Rounds on the Future of Public Health, Mailman School of Public Health: “Food Politics 2015: From Personal Responsibility to Policy Advocacy,” This is the opening talk in a month-long series of lectures on obesity prevention. 4:00-5:30 Alumni Auditorium, 650 West 168th Street. Free and open to the public.